Diaphragm for flush valves



Jan. 8, 1957 F. J. COLENDAR DIAPHRAGM FOR FLUSH VALVES Filed Oct. 51, 1952 lll,

22 E 20 23- /2 40 #E j 3 INVENToR. FRfDER/o/r J GOL ENUM ign/J1@ d-@pm ATTORNEYS United States ,Patent O DIAPHRAGM FOR FLUSH VALVES Frederick J. Colendar, Chicago, Ill., assignor to Sloan Valve Company, Chicago, Ill., a corporation of Illinois Application October 31, 1952, `Serial No. .318,059

1 Claim. (Cl. 251-40) This invention yrelates to diaphragms vfor ush valves and vhas for its object to provide a new and improved device of this type.

A further .object of the invention is to provide a new and improved ydiaphragm which will :quietly close upon its seat without objectionable closing ,noise or thump.

Another :object is to design an improved diaphragm which will close .quietly upon .the valve seat without requiring rvextensive changes in structure to produce the desired results.

A further object is to design a new and improved diaphragm for flush valves which will not require frequent replacement .or repair thereby reducing maintenance and servicing.

The invention has other objects more particularly pointed out in the yaccompanying description, which .together with the drawings shows a preferred embodiment of the invention. f

Fig. 1 is a view in section showing atflushvalve equipped with a diaphragm made according to the invention;

Fig. 2 isa bottom view of the diaphragm;

Fig. 3 is an enlarged section of a portion of the flush valve showing the diaphragm 'in valve closed position;

Fig. 4 is a fragmentary View of an old type .diaphragm showing the same some time after a period of use.

Referring more specically to Fig. l, there is illustrated a flush valve of well'known construction, the details of which need not be specically pointed out, except as it is concerned with the present invention. The valve consists of the casing 1, provided with an inlet Water supply connection 2 and an outlet 3, between which there is an interior cylindrical upstanding part 4, the upper edge of which forms the annular valve seat 5. The main valve indicated generally at 6 consists of a iiexible circular rubber diaphragm having a lower valve seating portion 7 which is clamped to the guiding member 8 slidably fitting into cylindrical part 4. The diaphragm 6 is provided with a central opening 9 and a clamping disc 10 is arranged with a threaded portion 11 projecting through the center opening 9 into the guiding member 8 to clamp the diaphragm 6 between them. Certain other details of the diaphragm 6 are preferably constructed in accordance with the teachings of Patent 1,714,573, issued May 28, 1929. An auxiliary valve 12 is carried by the clamping disc 10 and has a depending stem 13 which projects through the diaphragm opening 9 into the guiding member 8, the lower end being arranged opposite the actuating plunger 14, which is adapted to be pushed inwardly by the handle operator 15 to tilt the auxiliary valve 12 and open it from its seated position across the opening 9.

The casing 1 is provided with an external cover 20 and an internal cover 21, the external cover 20 being screw threaded to the casing 1 and provided with a shoulder 22 which engages the outer edge ofthe internal cover 2'1 and presses it downwardly against the` outer edge portion 23 of the diaphragm 6. The relatively thickened 2,776,812 Patented Jan. 8, 1.957

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outer .edge portion 23 of the diaphragm has a metal reinforcing ring 24 imbedded therein and .the valve seating portion 7 is also thickened `and is provided with a reinforcing ring 2S. The diaphragm 6 is preferably made of rubber and has a relatively thinner flexible connecting portion 26 extending between the outer edge portion 23 and the valve seatingv portion 7.

In the ordinary operation of the flush valve described, pressures are equalized below and above the diaphragm l6, the pressure in the chamber 27 above the diaphragm 6 being provided through the .small by-pass opening 32 in the diaphragm, and since the pressure area above the diaphragm in chamber 27 is greater `than rthat below the diaphragm from inlet 2, the diaphragm is held tightly against the valve seat 5, shutting olf the water ow between the inlet 2 and outlet 3. Now when the plunger pin 14 is actuated by the operating handle 15 and .the auxiliary valve 12 is tilted, the pressure above the diaphragm is relieved downward through the diaphragm central opening '91, so that the water pressure below the diaphragm 6 can now ex the diaphragm upward to open the valve .to permit water ow. To partly obviate noise, the valve seat 5 is constructed so that it tapers downward and outward from its inner edge 2 8 to the outer edge A29., .as shown in Fig. 3. With this former .type of diaphragm construction the inner edge of the diaphragm valve seating portion 7 first makes closing `contact with ,the inner .top edge .28 o f the valve seat 5 `and .then as the closing action continues, gradually closes onto lthe .seat progressively outward to the outer ,edge 29 until ythe full width .of the valve vseat 5 is closed or curved by the diaphragm seating portion 30. This action vetliectivlely helps to vreduce the closing noise by pinching were initially .installed .and thefdiaphragms were new.

However, after relatively long periods of operation, particularl-y under fairly high pressures, `the repeated closures of the diaphragm 6 Vupon the valve seat 5 resulted in wear on the seating portion 7, so that Agradually the impression 30 of the valve seat was formed in the rubber of the diaphragm, as shown in Fig. 4. As this wearing action continued, an overhanging lip or ridge 31 was gradually formed on the valve seating portion 7 opposite the outer edge 29 of the valve seat 5 and in some cases this ridge projected downward as much as one-sixteenth of an inch.

About the time that the wearing action on the diaphragm took place, it was noticed that the closing action of the flush Valve became noisy and gradually became very objectionable from the time it was first observed. The noise was noticeably described as a sharp knock or thump as if the diaphragm was slammed down on its seat just before it closed upon it. Many eierts were made to find what the cause was and attempts were made to correct this condition, but the only known remedy was to remove the old diaphragm and substitute a new one which corrected the condition for a time until operational wear again took place. This repeated maintenance and repair of the flush valves was a costly and burdensome problem, especially in hospitals, institutions and hotels where the noise created by the worn diaphragms was propagated throughout the buildings by the piping system and frequent servicing was therefore required.

Due to the fact that the formation of the overhanging lip or ridge 31 was not noticed at rst, since it projected such a short distance downward from the diaphragm 6, no particular significance was attached to it. However, after all attempts to correct the noise nally failed, a

further careful and minute inspection of the worn diaphragm seat 30 was made `and attention was then directed to the ridge formation 31. It was discovered that this projecting ridge 31 was the sole cause of the trouble and noise, and that in the closed position of the diaphragm, the ridge actually overlapped the outer edge 29 of the valve seat, as seen in Fig. 4. It is surmised that as this worn valve seating portion 30 approached the Valve seat 5, the increased velocity of the water passing over the gradually closing gap above the seat forced the flexible ridge 31 inward along with the ow stream until the valve seating portion 7 closed upon the inner edge 28 of the valve seat, whereupon the exible ridge 31 was rapidly eX- pelled outward by the squeezing action of the tapered valve seat 5. This rapid expelling of the ridge 31 outward caused the diaphragm 6 to slam down hard upon the valve seat resulting in the loud knock or thump It was then found that by removing the ridge 31 from the Worn diaphragm as by grinding it down, the thump was entirely removed and the iush valve again became quiet in operation similar to the action of a new diaphragm and repeated tests have verified this. By thereafter constructing the diaphragms according to the invention, further maintenance and servicing of the iush valves were greatly reduced, the objectionable noise created by the thump of the diaphragm was eliminated; and operational wear of the diaphragm minimized, all of which has contributed to longer service life of the diaphragm. The improvement consists in arranging the valve seat 5 as before with the tapered top surface of the same width and the seating portion 7 of the diaphragm arranged so that the seat contacting part is less in area or width than the valve seat 5, as clearly shown in Fig. 3. Expressed otherwise, the valve seat 5 is Wider than the valve seat ing part 7 of the diaphragm 6 that it closes upon. The remaining part of the valve seating portion 7 directly above the outer edge 29 of the valve seat 5 is provided with a tapered part 32, extending between the outer edge 29 of the valve seating portion 7 and merging with the thin flexible connecting portion 26 of the diaphragm 6 and never closes upon the valve seat 5. Since this tapered portion 32 is situated above the outer edge 29 of the valve seat 5, no ridge or projection can subsequently be formed in it as the valve seating portion 7 gradually wears down. The arrangement effectively eliminates the closing noise for the life of the diaphragm.

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What is claimed is:

In a Hush valve body provided with a water passage therethrough having an inlet and an outlet, said body having an upstanding generally cylindrical portion having an annular valve seat at the upper end thereof, said cylindrical portion being spaced inwardly Vfrom the body, a flexible disc-shaped diaphragm controlling the water passage through said body, said diaphragm having a relatively thick outer edge portion clamped in said body and having a central opening therein, said diaphragm also having a relatively thick inner circular portion surrounding said central opening and provided with an annular valve seat contacting surface, an auxiliary control valve arranged across said central opening, there being a relatively thinner annular portion of said diaphragm connecting said thick outer edge portion and said thick inner portion to enable said diaphragm to ex and move the valve seat contacting surface thereof to and from engagement with said valve seat, the width of said valve seat contacting surface on said diaphragm being less than the width of said valve seat and extending, when in the closed position, from the inner edge of said valve seat outward to less than the full width of said valve seat so that the outer edge of said valve seat contacting surface of the diaphragm does not overlap the valve seat, said diaphragm having an inclined surface surrounding and ex tending outwardly and upwardly from the outer peripheral edge of said valve seat contracting surface thereof, said inclined surface and said valve seat contacting surface and said valve seat being concentrically disposed with respect to each other with said inclined surface positioned to overlie in spaced relation the outer edge portion of said valve seat when said valve seat contacting surface of the diaphragm is in contact with said valve seat.

References Cited in the file of this patent UNITED STATES PATENTS Re. 20,576 Sloan Dec. 7, 1937 1,771,410 Landis July 29, 1930 1,939,911 McCune Dec. 19, 1933 2,035,693 Dorbrick Mar. 31, 1936 2,038,135 Sloan Apr. 2l, 1936 2,049,521 Sloan Aug. 4, 1936 2,302,930 Anderson Nov. 24, 1942 i. fr" 

